KR20200135977A - White ink, ink set, and recording method - Google Patents

Abstract

A bag ink containing a bag pigment, a polycarbonate urethane resin, a polyether urethane resin, and water, and a recording method using the bag ink are provided. In addition, the ink is provided with the back ink and at least one color ink, the color ink is an aqueous ink containing a colorant, and the difference in surface tension between the back ink and the color ink at 25°C is ± 0 to 3 mN/m. A set and a recording method using the ink set are provided.

Description

White ink, ink set, and recording method

The present invention relates to a white ink, an ink set, and a recording method.

Conventionally, as a textile printing method, hand dyeing and screen printing have been mainstream. However, in recent years, the case of using the printing method (inkjet printing method) using an inkjet printer is increasing.

As the colorant used in the inkjet printing method, a water-soluble dye can be mentioned. Water-soluble dyes have a mechanism to develop color by penetrating a colorant into the fiber, and have a clear color and a wide gamut that can be reproduced. On the other hand, a water-soluble dye has low light resistance; Steps such as fixing and washing with water after attaching the dye to the fiber are required; Treatment of waste dye liquid caused by water washing or the like is complicated; It has a drawback called. For this reason, instead of a water-soluble dye, the use of a water-insoluble colorant is attracting attention.

In the inkjet printing method using a white pigment as a water-insoluble colorant, a method of forming a color image by adhering a color ink further after forming a white base by attaching a white ink containing a white pigment to a fiber It is generally known. In particular, when a color ink other than white is directly printed on a dark fiber including black, the color of the color ink may not be recognized by the naked eye. For this reason, when printing with color ink on fibers of a color other than white, a white base is usually formed.

When a color ink is deposited on a white base to form a color image, if the whiteness of the base is low, the color development of the color image decreases. For this reason, the whiteness of the lower limb is preferably higher. In addition, the base formed on a recording material such as fabric, which is a structure of fibers, sometimes cracks when the recording material is stretched, which is one of the major problems. In addition, depending on the composition of the back ink, the back ink may be poorly printed, and the base may not be formed uniformly and may be observed as non-uniformity. The non-uniformity of the white base also causes a problem in that the quality of the color image formed thereafter is greatly deteriorated. For this reason, a back ink capable of solving these problems is strongly desired.

In addition, in the case of forming a color image having a solid portion by adhering color ink on a white base, depending on the combination of the back ink and the color ink, the color ink is poorly printed and the color appears to have white streaks. An image may be obtained. For this reason, there is a strong demand for an ink set capable of solving this problem.

In Patent Documents 1 and 2, an ink containing a white pigment is disclosed.

Japanese Patent Publication No. 2018-505244 Japanese Unexamined Patent Publication No. 2017-31354

An object of the present invention is to provide a back ink capable of forming a substrate having high whiteness, less cracking even when a recording material is stretched, and having less unevenness, and a recording method using the back ink. Another object of the present invention is to provide an ink set capable of forming a color image with good non-printing, and a recording method using the ink set when a color ink is adhered on a base formed with a back ink. To

Specific means for solving the above problems include the following embodiments.

One)

Bag ink containing a white pigment, a polycarbonate urethane resin, a polyether urethane resin, and water.

2)

The back ink according to 1) above, further containing a water-soluble organic solvent.

3)

The back ink according to 1) or 2) above, which further contains a surfactant.

4)

The bag ink according to 3) above, wherein the surfactant is at least one surfactant selected from acetylene glycol and polyalkylene glycol.

5)

The white ink according to any one of the above 1) to 4), wherein the total content of the polycarbonate urethane resin and the polyether urethane resin is 10 to 20 mass%.

6)

The back ink according to any one of the above 1) to 5) and one or more kinds of color inks are provided,

The color ink is an aqueous ink containing a colorant other than a white pigment,

An ink set in which the difference in surface tension between the back ink and the color ink at 25° C. is ±0 to 3 mN/m.

7)

A recording method in which recording is performed by attaching the back ink according to any one of the above 1) to 5) to a recording material.

8)

The recording method according to 7), wherein recording is performed by discharging the back ink by an ink jet printer and attaching it to the recording material.

9)

A recording method in which recording is performed by attaching each ink included in the ink set according to 6) to a recording material.

10)

The recording method according to 9), wherein recording is performed by discharging each ink included in the ink set by an ink jet printer and attaching it to the recording material.

11)

The recording material is a fiber selected from the group consisting of polyester fibers, cellulose fibers, polyamide fibers, and natural fibers, blended fibers containing these fibers, or fabrics containing these fibers. The recording method according to any one of the preceding claims.

12)

Fibers to which the back ink according to any one of 1) to 5) is adhered above.

13)

Fibers to which both the back ink and one or more kinds of color inks provided in the ink set according to 6) are adhered.

Advantageous Effects of Invention According to the present invention, it is possible to provide a back ink capable of forming a base having high whiteness, less cracking even when a recording material is stretched, and less unevenness, and a recording method using the back ink. Further, according to the present invention, it is possible to provide an ink set capable of forming a color image excellent in non-printing, and a recording method using the ink set when a color ink is adhered on a base formed with a back ink. .

In the present specification, "parts" and "%" are all expressed on a mass basis including examples, unless otherwise noted. In addition, "C.I." means a color index.

<Back Ink>

The back ink according to this embodiment contains a white pigment, a polycarbonate urethane resin, a polyether urethane resin, and water.

(White pigment)

It does not specifically limit as a white pigment, For example, White inorganic pigments, such as titanium oxide, zinc oxide, zinc sulfide, antimony oxide, and zirconium oxide; White organic pigments such as white hollow resin particles and polymer particles; And the like. In a specific example, C.I. Pigment White 1 (basic lead carbonate), C.I. Pigment White 4 (zinc oxide), C.I. Pigment White 5 (mixture of zinc sulfide and barium sulfate), C.I. Pigment White 6 (titanium oxide), C.I. Pigment White 6:1 (titanium oxide containing other metal oxides), C.I. Pigment White 7 (zinc sulfide), C.I. Pigment White 18 (calcium carbonate), C.I. Pigment White 19 (clay), C.I. Pigment White 20 (Mica Titan), C.I. Pigment White 21 (barium sulfate), C.I. Pigment White 22 (natural barium sulfate), C.I. Pigment White 23 (gloss white), C.I. Pigment White 24 (alumina white), C.I. Pigment White 25 (gypsum), C.I. Pigment White 26 (magnesium oxide·silicon oxide), C.I. Pigment White 27 (silica), C.I. Pigment White 28 (anhydrous calcium silicate), etc. are mentioned.

Further, since the surface-treated titanium oxide tends to be excellent in color development and hiding properties, titanium oxide surface-treated with silica or alumina can also be used. The rutile type is preferable as the crystal form of titanium oxide. As a specific example, Tipaque (registered trademark) R-580, R-670, R-780, R-850, R-855, CR-60 (above, manufactured by Ishihara Industrial Co., Ltd.); JR-301, JR-403, JR-405, JR-804, JR-806, JR-600A, JR-800 and the like (above, manufactured by Teika Corporation), and the like.

The white pigment can also be obtained as a dispersion (slurry) in an already dispersed state. Examples of such a dispersion include TF-5760 WHITE (D2B) (a titanium oxide slurry manufactured by Dainichi Purification Industries, Ltd., a titanium oxide solid content concentration: 60%, an average particle diameter: 300 nm), and the like.

Moreover, it is also possible to disperse the white pigment in a solid state using a dispersant to obtain a dispersion. The dispersant is not particularly limited, and various known dispersants can be used depending on the purpose. As a specific example, styrene and its derivatives; Vinyl naphthalene and derivatives thereof; aliphatic alcohol esters of α,β-ethylenically unsaturated carboxylic acids; (Meth)acrylic acid and derivatives thereof; Maleic acid and its derivatives; Itaconic acid and its derivatives; Paric acid and its derivatives; A copolymer composed of at least two monomers selected from the group consisting of vinyl acetate, vinyl alcohol, vinylpyrrolidone, (meth)acrylamide, and derivatives thereof (preferably, at least one is a hydrophilic monomer); And the like. Examples of the copolymer include block copolymers, random copolymers, graft copolymers, and salts thereof.

In addition, in this specification, "(meth)acrylic acid" is used as meaning including both "acrylic acid" and "methacrylic acid". Moreover, "(meth)acrylamide" is used as the meaning including both "acrylamide" and "methacrylamide".

The dispersant may be synthesized or may be obtained as a commercial item. As a specific example of a commercial item, Joncryl 62, 67, 68, 678, 687 (all are styrene-acrylic resins manufactured by Johnson Polymer); Movinyl S-100A (modified vinyl acetate resin manufactured by Hoechst Synthetic Corporation); Jurima AT-210 (polyacrylic acid ester copolymer manufactured by Nihon Pure Chemical Industries, Ltd.); And the like. Moreover, as an A-B block polymer, the dispersing agent etc. disclosed in International Publication No. 2013/115071 are mentioned, for example.

(Polycarbonate urethane resin)

Examples of the polycarbonate urethane resin include resins obtained by reacting polyols or polycarbonate polyols with polyisocyanates. Among these, a resin obtained by reacting a polyol and a polyisocyanate is preferable.

The polyol is not particularly limited as long as it is a compound having two or more hydroxy groups in one molecule. Among them, alkanediol is preferred, C2-C20 alkanediol is more preferred, C2-C10 alkanediol is still more preferred, and C4-C6 alkanediol is particularly preferred. The alkanediol may be linear, branched, or cyclic. Among them, linear or branched chain alkanediol is preferable. Specific examples include ethylene glycol, propylene glycol, 1,3-propanediol, butanediol, pentanediol, hexanediol, 3-methyl-1,5-pentanediol, heptanediol, octanediol, undecanediol, dodecanediol And the like.

The polycarbonate polyol is not particularly limited, and is a compound obtained by transesterification reaction between a carbonate ester and a polyol in the presence of a catalyst; A compound obtained by reacting phosgene and bisphenol A; And the like. Examples of the carbonate ester include methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, and diphenyl carbonate. Examples of the polyol include ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, Low molecular weight diol compounds such as neopentyl glycol and 1,4-cyclohexanediol; Polyethylene glycol and polypropylene glycol; And the like.

It does not specifically limit as a polyisocyanate, It can select suitably according to a purpose. Specific examples include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate, 4,4'-diphenylenemethanedi Isocyanate (MDI), 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl Aromatic polyisocyanate compounds such as -4,4'-diisocyanatodiphenylmethane, 1,5-naphthylenediisocyanate, m-isocyanatophenylsulfonyl isocyanate, and p-isocyanatophenylsulfonyl isocyanate; Ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecan triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, bis(2-isocyanatoethyl)fumarate, bis(2-isocyanatoethyl)carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexano Aliphatic polyisocyanate compounds such as eight; Isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis(2-isocyanato) Alicyclic diisocyanate compounds such as ethyl)-4-cyclohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, and 2,6-norbornane diisocyanate; And the like. Among these, alicyclic diisocyanate is preferable.

Commercially available products of the polycarbonate urethane resin include Ucoat UX-320, 390, Parmarin UA-368 (above, manufactured by Sanyo Chemical Co., Ltd.), and Hydran WLS-201 (manufactured by DIC Corporation).

(Polyether urethane resin)

As a polyether urethane resin, a resin obtained by making a polyether which has two hydroxyl groups in a molecule|numerator and a polyisocyanate react is mentioned. Among these, examples of the polyisocyanate include the polyisocyanates described in the section of the polycarbonate urethane resin, and the same ones including preferred ones.

Polyethers having two hydroxyl groups in the molecule include poly(oxyalkylene) glycol. The poly(oxyalkylene) glycol may be linear, branched, or cyclic, preferably linear or branched, and more preferably linear. The number of carbon atoms in the alkylene moiety is usually C2-C12, preferably C2-C10, more preferably C2-C8, still more preferably C2-C6, and particularly preferably C4-C6. When a plurality of alkylene moieties are present, the number of carbon atoms of these alkylenes may be the same or different. The number of repetitions of "oxyalkylene" in the poly(oxyalkylene) glycol is usually 2 to 40, preferably 2 to 30, more preferably 2 to 20, and still more preferably 2 to 15.

As a commercial product of a polyether urethane resin, NeoRez R-967 (manufactured by Kusumoto Chemical Co., Ltd.), Parmarin UA-150 (manufactured by Sanyo Chemical Industry Co., Ltd.), etc. are mentioned.

(water)

As water, it is preferable to use water having few impurities such as metal ions and inorganic salts. As such water, ion-exchanged water, distilled water, etc. are mentioned.

(Water-soluble organic solvent)

It is preferable that the back ink according to this embodiment further contains a water-soluble organic solvent. It does not specifically limit as a water-soluble organic solvent, Polyhydric alcohol, pyrrolidone, etc. are mentioned.

Examples of polyhydric alcohols include C3-C6 polyhydric alcohols having 2 or 3 hydroxyl groups; Polyalkylene glycol having a repeating unit of 2 or more and a molecular weight of about 20000 or less, preferably a liquid polyalkylene glycol, more preferably a poly C2-C4 alkylene glycol, still more preferably a poly C2-C3 alkylene glycol; Alkyl ether of polyalkylene glycol, preferably monoalkyl ether of polyalkylene glycol; Alkylene oxide adducts of glycerin; Alkylene oxide adducts of diglycerin; And the like.

Examples of C3-C6 polyhydric alcohols having 2 or 3 hydroxy groups include glycerin, propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,2-pentanediol, 1, 3-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, etc. are mentioned.

Examples of the polyalkylene glycol having a repeating unit of 2 or more and a molecular weight of about 20000 or less include diethylene glycol, triethylene glycol, and polyethylene glycol (PEG200, PEG400, PEG800, etc.); Dipropylene glycol, tripropylene glycol, and polypropylene glycol; UniLube 50TG-32 (manufactured by Nichiyu Corporation); And the like.

Examples of the polyalkylene glycol alkyl ether include compounds in which the hydroxy group of the polyalkylene glycol described above is substituted with an alkyl group. Examples of the alkyl group include linear, branched, or cyclic alkyl groups. Among these, a linear or branched alkyl group is preferable, and a linear alkyl group is more preferable. The number of carbon atoms in the alkyl group is usually C1-C6, preferably C1-C4. As a specific example, butyl diglycol etc. are mentioned.

As the alkylene oxide in the alkylene oxide adduct of glycerin, usually C2-C4, preferably C2-C3 alkylene oxide. The mass average molecular weight of these compounds is usually 300 to 5000, preferably 340 to 4500. The mass average molecular weight can be measured by GPC (gel permeation chromatography). As a specific example of a commercial item, Sanyx GP series (manufactured by Sanyo Chemical Industries, Ltd.); Blaunon GL series (manufactured by Aoki Oil Industry Co., Ltd.); Wilbright S-753 (manufactured by Nichiyu Corporation); And the like.

As the alkylene oxide in the alkylene oxide adduct of diglycerin, usually C2-C4, preferably C2-C3 alkylene oxide is mentioned. The mass average molecular weight of these compounds is usually 300 to 5000, preferably 340 to 4500. As a specific example of a commercial item, SC-P400, SC-P750, SC-P1000, SC-P1200, SC-P1600; SC-E450, SC-E750, SC-E1000, SC-E1500, SC-E2000, SC-E3000, SC-E4500 (above, manufactured by Sakamoto Pharmaceutical Industries, Ltd.); UniLube DGP-700, DGP-700F (above, manufactured by Nichiyu Corporation); And the like.

Examples of pyrrolidones include 2-pyrrolidone and N-methyl-2-pyrrolidone.

(Surfactants)

It is preferable that the bag ink according to the present embodiment further contains a surfactant. By containing a surfactant, an increase in the viscosity of the back ink, aggregation of components, and the like are suppressed, and storage stability is improved. Although the kind of surfactant is not particularly limited, for example, at least one surfactant selected from acetylene glycol and polyalkylene glycol is preferred. Among these, when a polyalkylene glycol is used, the whiteness and lagging tend to become good.

As an acetylene glycol surfactant, for example, 2,4,7,9-tetramethyl-5-decine-4,7-diol, 2,4,7,9-tetramethyl-5-decine-4,7 -A surfactant selected from diol, 2,4-dimethyl-5-decin-4-ol, 2,4-dimethyl-5-decin-4-ol, or alkylene oxide adducts thereof is preferred. Examples of the alkylene oxide include a C2-C4 linear, branched, or cyclic alkylene oxide. Among these, a linear or branched alkylene oxide is preferable. Moreover, what contains an ether, for example, 2,5,8,11-tetraethyl-6-dodecine-5,8-diolethoxylate may be sufficient. As a specific example of a commercial item, Orphine series (made by Air Products), such as Orphine 104, 104PG50, E1010; Dynol series such as Dynol 604 and 607 (manufactured by Air Products); Sapinol series such as safinol 440, 465, and 61 (manufactured by Nisshin Chemical Industries, Ltd.); And the like.

Polyalkylene glycol surfactants include, for example, polyoxyethylene alkyl ether, fatty acid ethylene oxide adduct, higher alkylamine ethylene oxide adduct, and polyoxyalkylene glycol (preferably polyoxy C2-C4 alkylene Glycols, more preferably polyoxyethylene polyoxypropylene glycol). Among these, polyoxyalkylene glycol is preferable.

Examples of the polyoxyethylene alkyl ether include polyoxyalkylene branched decyl ether, polyoxyalkylene tridecyl ether, polyoxyethylene isodecyl ether, and polyoxyalkylene lauryl ether. As a specific example of a commercial item, Neugen XL-40, 50, 60, 70, 80, 100, 140, 160, Neugen TDS-30, 50, 70, 80, 90, 100, 120, Hytenol LA-10 , LA-12, LA-16, PS-06, PS-15 (above, manufactured by Daiichi Pharmaceutical Co., Ltd.), and the like.

Examples of fatty acid ethylene oxide adducts include ethylene stearate oxide adducts and polyethylene glycol lauric acid esters. As a specific example of a commercial item, Emanon 1112, 3199V, 3299V, 3299VR, 3201M-V (above, Kao Corporation make), etc. are mentioned.

Commercially available products of higher alkylamine ethylene oxide adducts include Amit 102, 105, 105A, 302, 320 (above, manufactured by Kao Corporation).

As a commercial product of polyoxyalkylene glycol, Emargen PP-290 (manufactured by Kao Corporation, a copolymer of 160/30 polyethylene glycol/polypropylene glycol); Newpol PE-61, PE-62, PE-64, PE-68, PE-71, PE-74, PE-75, PE-78, PE-108 (manufactured by Sanyo Chemical Industries, Ltd., polyoxyethylene polyoxypropylene block Polymer); Epan 410, 420, 450, 485, 680, 710, 720, 740, 750, 785, U-103, U-105, U-108 (manufactured by Daiichi Pharmaceutical Co., Ltd., the mass average molecular weight of polypropylene glycol is about 950 -4000, polyoxyethylene polyoxypropylene glycol in which the content of polyoxyethylene is about 5 to 95%; And the like.

(Ink Formulation)

The back ink according to the present embodiment may further contain an ink preparation agent other than the above, if necessary. Examples of ink preparations include anti-fog agents, preservatives, pH adjusters, chelating agents, rust inhibitors, water-soluble ultraviolet absorbers, water-soluble polymer compounds, and antioxidants.

Examples of the anti-foaming agent include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, ethyl p-hydroxybenzoate, 1,2-benzisothiazolin-3-one, and salts thereof. I can.

Preservatives include, for example, organic sulfur, organic nitrogen sulfur, organic halogen, haloarylsulfone, iodinepropargyl, haloalkylthio, nitrile, pyridine, 8-oxyquinoline, benzothiazole, Isothiazoline, dithiol, pyridine oxide, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiazine, anilide, adamantane, dithiocarbamate, bromide indanone And benzyl bromine acetate-based and inorganic salt-based compounds.

As an organohalogen type compound, pentachlorophenol sodium is mentioned, for example.

As a pyridine oxide compound, 2-pyridinethiol-1-oxide sodium can be mentioned, for example.

As an isothiazoline-based compound, for example, 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4 -Isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazoline-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazoline-3-one calcium chloride, 2 -Methyl-4-isothiazoline-3-one calcium chloride, etc. are mentioned.

Other antiseptic and anti-fogant agents include anhydrous sodium acetate, sodium sorbate, sodium benzoate, and the brand names Proxel GXL(S) manufactured by Arch Chemical Co., Ltd., and Proxel XL-2(S).

As the pH adjuster, any substance can be used as long as it does not adversely affect the prepared ink and can control the pH of the ink in the range of, for example, 5 to 11. Examples of the pH adjuster include hydroxides of alkali metals, hydroxides of alkaline earth metals, aliphatic amine compounds, and alcoholamine compounds.

Lithium hydroxide, sodium hydroxide, potassium hydroxide, etc. are mentioned as an alkali metal hydroxide. Examples of the alkaline earth metal hydroxide include beryllium hydroxide, magnesium hydroxide, calcium hydroxide, and strontium hydroxide. Among these, hydroxides of alkali metals are preferable, and lithium hydroxide and sodium hydroxide are more preferable.

Examples of the aliphatic amine compound include ammonia, monomethylamine, dimethylamine, trimethylamine, monoethylamine, dimethylamine, trimethylamine, and the like, preferably ammonia or triethylamine.

Examples of the alcoholamine compound include monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, methylethanolamine, dimethylethanolamine, and N-methyldiethanolamine, and preferred Preferably, they are tertiary amines, More preferably, they are triethanolamine.

Other specific examples include carbonates of alkali metals such as lithium carbonate, sodium carbonate, sodium hydrogen carbonate, and potassium carbonate; Alkali metal salts of organic acids such as sodium silicate and potassium acetate; Phosphates such as disodium phosphate; And the like.

Examples of the chelating reagent include disodium ethylenediamine tetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediamine triacetate, sodium diethylenetriamine pentate, sodium uracildiacetate, and the like.

Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropyl ammonium nitrite, pentaerythritol tetranitrate, dicyclohexyl ammonium nitrite, and the like.

Examples of the water-soluble ultraviolet absorber include sulsaturated benzophenone compounds, benzotriazole compounds, salicylic acid compounds, cinnamic acid compounds, and triazine compounds.

Examples of the water-soluble high molecular compound include polyvinyl alcohol, cellulose derivatives, polyamines, and polyimines.

As the antioxidant, various organic and metal complex-based anti-fading agents can be used, for example. Examples of the organic anti-fading agent include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indans, chromanes, alkoxyanilines, and heterocyclics.

(Content of each component)

Each of the components described above may be used singly or in combination of two or more. The content rate of each component in the total mass of the bag ink according to the present embodiment (the sum of the two or more compounds is included) is, for example, as follows. In addition, the balance other than these is water.

White pigment:

Usually 1 to 30%, preferably 5 to 20%, more preferably 5 to 15%.

Polycarbonate urethane resin:

Usually 1 to 30%, preferably 5 to 20%, more preferably 5 to 15%.

Polyether urethane resin:

Usually 1 to 30%, preferably 1 to 20%, more preferably 1 to 15%.

Water Soluble Organic Solvent:

Usually 0 to 50%, preferably 15 to 35%, more preferably 20 to 30%.

Surfactants :

Usually 0 to 5%, preferably 0.2 to 2%, more preferably 0.5 to 1%.

Ink Formulation:

Usually 0 to 5%, preferably 0.2 to 2%, more preferably 0.5 to 1%.

The total content of the polycarbonate urethane resin and the polyether urethane resin is preferably 10 to 20% by mass.

When the white ink according to the present embodiment contains a dispersant, the content of the dispersant with respect to 1 part of the white pigment is usually 0.1 to 1 part, preferably 0.1 to 0.6 parts, and more preferably 0.2 to 0.5 parts.

(How to prepare the back ink)

The method for preparing the bag ink according to the present embodiment is not particularly limited, and a known method may be employed. As an example, the method of preparing a back ink by adding and stirring each component is mentioned. In the case of using a white pigment having no self-dispersibility, a method of initially mixing a white pigment, a dispersant, and water to prepare a dispersion, and then adding and stirring the remaining components may be employed.

If necessary, the obtained bag ink may be subjected to microfiltration by a known method to separate solid impurities by filtration. For example, when discharging the bag ink according to the present embodiment by an inkjet printer, it is preferable to perform microfiltration.

The back ink according to the present embodiment has a high degree of whiteness, does not easily crack even when the recording material is stretched, and is capable of forming a base with less unevenness, so it is an ink for forming a white base, especially fibers. Very useful as a back ink for dragons.

In addition, the back ink according to the present embodiment can suppress fluff formation of fibers to which the back ink has adhered as an effect other than the above. For this reason, when an image is printed on the pretreated fiber, an image excellent in sharpness can be obtained. Moreover, the abrasion resistance and washing fastness of the recorded image can be improved.

<recording method>

The recording method according to the present embodiment using the above-described back ink is to perform recording by attaching the above-described back ink to a recording material. The method of attaching the back ink to the recording material is not particularly limited, and a brush, brush, roll coater, bar coater, inkjet printer, or the like may be used depending on the purpose. In the case of using an inkjet printer, recording can be performed by discharging the back ink by an inkjet printer and attaching it to a recording material.

The material to be recorded is not particularly limited, but fibers and fabrics thereof are preferred.

The type of fiber is not particularly limited. Examples thereof include fibers selected from the group consisting of polyester, cellulose, polyamide, and natural fibers, or blended fibers thereof. Examples of polyester fibers include fibers containing polyethylene terephthalate as a main component. Examples of the cellulose fibers include cotton, cotton, rayon, triacetate fibers, and diacetate fibers. Examples of the polyamide fibers include nylon fibers. Examples of natural fibers include silk and wool.

The fiber may be formed with an ink receiving layer (spread prevention layer). A method of forming an ink-receiving layer on a fiber is known, and such fiber can be purchased as a commercial item. Moreover, it is also possible to form an ink-receiving layer on the fiber by appropriately selecting a constituent component, a forming method, and the like from a known common technique. The ink receiving layer is not particularly limited as long as it has the function.

As the color of the fiber, all dark colors and light colors can be mentioned. Further, if necessary, back ink may be attached to the white fiber.

After attaching the back ink to the fibers, the fibers can be dried, if necessary. Drying of the fibers can be carried out at room temperature (about 25°C) to 200°C, preferably room temperature to 180°C for several minutes. By setting the drying temperature to 110° C. or higher, the fixability of the ink to the fibers tends to be improved. Further, by setting the heating temperature to 200°C or less, it is possible to prevent deterioration due to heat of the components contained in the fiber and the back ink.

<Ink set>

The ink set according to the present embodiment includes a back ink and at least one color ink, and the color ink is an aqueous ink containing a colorant other than a white pigment, and the surface tension of the back ink and the color ink at 25°C The difference is ± 0 to 3 mN/m. The difference in surface tension is preferably ±0 to 2.5 mN/m, more preferably ±0 to 2 mN/m. Usually, the surface tension of the back ink is equal to or greater than the surface tension of the color ink.

In this specification, the surface tension at 25°C of each ink is measured by the plate method using a CBVP-Z type surface tension meter manufactured by Kyowa Interface Science Co., Ltd. The number of digits after the decimal point of the obtained measured value is rounded off and this is taken as the surface tension of each ink.

The kind of color ink included in the ink set according to this embodiment is not particularly limited. For example, in addition to the back ink, an ink set provided with four color inks of yellow, red, blue, and black may be used. Further, if necessary, in addition to the above four colors, an ink set may be further provided with at least one color ink such as green, violet, orange, and brown.

[Back Ink]

Since the back ink included in the ink set according to the present embodiment is as described above, detailed description is omitted.

The surface tension at 25°C of the back ink is usually 31 to 35 mN/m, and preferably 32 to 34 mN/m.

[Color ink]

The color ink is not particularly limited as long as it is an aqueous ink containing a colorant other than a white pigment. Known dyes and pigments can be mentioned as the colorant. Among them, C.I. A numbered colorant is preferable, and a water-insoluble colorant is more preferable. As water, it is preferable to use water having few impurities such as metal ions and inorganic salts. As such water, ion-exchanged water, distilled water, etc. are mentioned.

(Water-insoluble colorant)

In the present specification, the water-insoluble colorant means that the solubility in water at 25°C is usually 3 g/L or less, preferably 1 g/L or less, more preferably 500 mg/L or less, even more preferably 100 mg /L or less means a colorant. As such a colorant, C.I. Disperse, C.I. And a colorant selected from solvents and pigments. Among these, pigments are preferred. Examples of the pigment include inorganic pigments, organic pigments and extender pigments.

Examples of the inorganic pigment include carbon black, metal oxide, metal hydroxide, metal sulfide, ferrocyanide, and metal chloride. Among these, as a black pigment, carbon black is preferable. Examples of the carbon black include thermal black, acetylene black, oil furnace black, gas furnace black, lamp black, gas black, and channel black. Among these, acetylene black, oil furnace black, gas furnace black, lamp black, and channel black are preferable. As a specific example of a commercial item, Raven series (manufactured by Colombia Carbon Corporation); Monarch series, Regal series, Mogul series (above, manufactured by Cabot); Color Black series, Printex series, Special Black series (above, manufactured by Degussa); MA series, MCF series (above, manufactured by Mitsubishi Chemical Corporation); And the like.

As an organic pigment, for example, an azo pigment having at least one azo group in a molecule, a phthalocyanine pigment, a quinacridone pigment, an isoindolinone pigment, a dioxazine pigment, a perylene pigment, a perinone pigment, a thioindigo pigment, And an anthraquinone pigment and a quinophthalone pigment. Among these, C.I. Pigments selected from pigments are preferred. In a specific example, C.I. Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 24, 55, 73, 74, 75, 83, 93, 94, 95, 97, 98, 108, 114, 128, 129, 138 , 139, 150, 151, 154, 155, 180, 185, 193, 199, 202; C.I. Pigment Red 5, 7, 12, 48, 48: 1, 57, 88, 112, 122, 123, 146, 149, 150, 166, 168, 177, 178, 179, 184, 185, 202, 206, 207 , 254, 255, 257, 260, 264, 272; C.I. Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 22, 25, 60, 66, 80; C.I. Pigment violet 19, 23, 29, 37, 38, 50; C.I. Pigment Orange 13, 16, 34, 36, 43, 68, 69, 71, 73; C.I. Pigment Green 7, 36, 54; C.I. Pigment Black 1, 7; And the like.

As an extender pigment, silica, calcium carbonate, talc, clay, barium sulfate, white carbon, etc. are mentioned, for example.

As a water-insoluble colorant, C.I. Pigments selected from pigments and carbon black are preferred, and C.I. Pigment Yellow, C.I. Pigment Red, C.I. Pigment Blue, C.I. Pigment Violet, C.I. Pigment Orange, and C.I. Pigments selected from pigment green are more preferred.

As the water-insoluble colorant, a single colorant is usually used. However, if necessary, you may use two or more types of coloring agents together. As an example, an organic pigment and an extender pigment; Organic pigments and inorganic pigments; Combination examples of such as are mentioned. Moreover, in order to improve fluidity, an extender pigment can also be used together in addition to an organic pigment and an inorganic pigment. Further, in order to adjust the hue of the dyed product, two or more colorants selected from inorganic pigments and organic pigments may be used in combination. Hue adjustment is to obtain a dyed product to which shade was applied; Broadening the gamut of dyeing; It is implemented for the purpose of, etc. For this purpose, various kinds of organic pigments can be used in combination and adjusted to a desired color.

(Dispersant)

When the color ink contains a water-insoluble colorant, it is preferable to further contain a dispersant.

Although it does not specifically limit as a dispersing agent, As a polymerization initiator, the mixture of an organic tellurium compound represented by following formula (1) and an organic ditellurium compound represented by following formula (2), or an organic tellurium compound represented by following formula (1) and an azo system An AB block polymer obtained by copolymerizing by a living radical polymerization method using any of a mixture of a polymerization initiator and an organic ditelluric compound represented by the following formula (2) is preferable. In addition, the A-B block polymer means a polymer in which the A polymer and the B polymer are chemically bonded, and the A polymer and the B polymer mean a polymerized polymer in which different monomers are respectively polymerized.

[Formula 1]

(In formula (1), R ¹ represents a C1-C8 alkyl group, an aryl group, a substituted aryl group, or an aromatic heterocyclic group. R ² and R ³ each independently represent a hydrogen atom or a C1-C8 alkyl group. R ⁴ represents an aryl group, a substituted aryl group, an aromatic heterocyclic group, an acyl group, an amide group, an oxycarbonyl group, or a cyano group.)

[Formula 2]

(In formula (2), R ¹ represents the same meaning as R ¹ in the formula (1).)

In the formula (1), the C1-C8 alkyl group for R ¹ is a methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, sec-butyl group, tert-butyl group , A linear, branched, or cyclic alkyl group having 1 to 8 carbon atoms such as a cyclobutyl group, n-pentyl group, n-hexyl group, n-heptyl group, and n-octyl group. Preferably, it is a C1-C4 linear or branched alkyl group, More preferably, it is a methyl group, an ethyl group, or an n-butyl group.

Examples of the aryl group for R ¹ include a phenyl group and a naphthyl group, and preferably a phenyl group.

Examples of the substituted aryl group for R ¹ include a phenyl group having a substituent and a naphthyl group having a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an alkoxy group, an amino group, a nitro group, a cyano group, and -CORa (Ra represents a C1-C8 alkyl group, an aryl group, a C1-C8 alkoxy group, or an aryloxy group.) A bonyl-containing group, a sulfonyl group, a trifluoromethyl group, etc. are mentioned. Among these, a trifluoromethyl group is preferable. The number of these substituents is usually 1 or 2. When the aryl group is a phenyl group, it is preferable to have a substituent at the para position or the ortho position.

Examples of the aromatic heterocyclic group for R ¹ include a pyridyl group, a pyrrole group, a furyl group, and a thienyl group.

In the formula (1), examples of the C1-C8 alkyl group for R ² or R ³ include the same C1-C8 alkyl group for R ¹ .

The formula (1) of, R ⁴ an aryl group, a substituted aryl group, and an aromatic heterocyclic group in, there may be mentioned the same groups each represented by R ^1.

Examples of the acyl group for R ⁴ include a formyl group, an acetyl group, and a benzoyl group.

Examples of the amide group for R ⁴ include carboxylic acid amide groups such as acetamide group, malonamide group, succinamide group, maleamide group, benzamide group, and 2-fluamide group; Thioamide groups, such as a thioacetamide group, a hexanedithioamide group, a thiobenzamide group, and a methanethiosulfonamide group; Selenoamide groups such as selenoacetamide group, hexanediselenamide group, selenobenzamide group, and methane selenosulfonamide; N-substituted amide groups such as N-methylacetamide group, benzanilide group, cyclohexanecarboxanilide group, and 2,4'-dichloroacetanilide group; And the like.

Examples of the oxycarbonyl group for R ⁴ include a group represented by -COORb (Rb represents a hydrogen atom, a C1-C8 alkyl group, or an aryl group.). Specific examples include a carboxyl group, a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an n-butoxycarbonyl group, a sec-butoxycarbonyl group, a tert-butoxycarbonyl group, an n-pentoxycarbonyl group, a phenoxycarbonyl group, and the like. have. Among these, preferably, they are a methoxycarbonyl group and an ethoxycarbonyl group.

As a preferred specific example of the organic tellurium compound represented by the above formula (1), R ¹ is a C1-C4 alkyl group, R ² and R ³ are each independently a hydrogen atom or a C1-C4 alkyl group, and R ⁴ is an aryl group, And compounds which are substituted aryl groups or oxycarbonyl groups. In a more preferred embodiment, R ¹ is a C1-C4 alkyl group, R ² and R ³ are each independently a hydrogen atom or a C1-C4 alkyl group, and R ⁴ is a phenyl group, a substituted phenyl group, a methoxycarbonyl group, or an ethoxycarbonyl group. And compounds.

As a specific example of the organic tellurium compound represented by the above formula (1), for example, (methyltellanylmethyl)benzene, (1-methyltellanylethyl)benzene, 1-chloro-4-(1-methyltellanyl) Ethyl)benzene, 1-trifluoromethyl-4-(1-methyltellanylethyl)benzene, 3,5-bis-trifluoromethyl-1-(1-methyltelanylethyl)benzene, 1,2, 3,4,5-pentafluoro-6-(1-methyltellanylethyl)benzene, 2-methyltelanylpropionitrile, (2-methyltelanylpropyl)benzene, methyl2-methyltelanyl-2- Methyl-propionate, ethyl 2-methyltelanyl-2-methyl-propionate, 2-methyltelanyl-2-methyl-propionitrile, and the like. Further, all of the compounds in which the methyltellanyl portion of the above compound is changed to ethyltellanyl, n-butyltelanyl, n-octyltelanyl, or the like is also included. In addition, all of the organic tellurium compounds described in International Publication No. 2004/014962 (page 4, page 25, page 7, page 18, line) can be illustrated.

The organic tellurium compound represented by the above formula (1) can obtain a polymer having a target number average molecular weight by appropriately adjusting its usage amount. The preferred amount is generally the mass (unit: grams) of the raw material vinyl monomer divided by the number average molecular weight of the target polymer (unit of the used amount is the number of moles), and in some cases, about 0.3 to 3 times the value It is preferable to use a quantity.

Further, depending on the kind of the vinyl-based monomer to be polymerized, in addition to the organic tellurium compound represented by the formula (1) used as a polymerization initiator, a ditelluric compound represented by the formula (2) may be further added.

Specific examples of the ditelluride compound represented by the above formula (2) include dimethylditelluride, diethylditelluride, di-n-propylditelluride, diisopropylditelluride, dicyclopropylditelluride, Di-n-butylditelluride, di-sec-butylditelluride, di-tert-butyltelluride, dicyclobutyltelluride, diphenylditelluride, bis-(p-methoxyphenyl)ditelluride , Bis-(p-aminophenyl)ditelluride, bis-(p-nitrophenyl)ditelluride, bis-(p-cyanophenyl)ditelluride, bis-(p-sulfonylphenyl)ditelluride , Dinaphthylditelluride, dipyridylditelluride, and the like. Among these, dimethylditelluride, diethylditelluride, di-n-propylditelluride, di-n-butylditelluride, and diphenylditelluride are preferable, and dimethylditelluride and diethyl Ditelluride, di-n-propylditelluride, and di-n-butylditelluride are more preferred.

When using the ditelluric compound represented by the above formula (2), the amount used is usually 0.01 to 100 mol, preferably 0.1 to 100 mol, when the total amount of the organic tellurium compound represented by the formula (1) is 1 mol. It is 10 mol, more preferably 0.1 to 5 mol.

As a polymerization initiator, you may use an azo polymerization initiator in addition to the said organic tellurium compound. The azo polymerization initiator is not particularly limited as long as it is an initiator used for conventional radical polymerization, and examples include 2,2'-azobis(isobutyronitrile) (AIBN), 2,2'-azobis( 2-methylbutyronitrile) (AMBN), 2,2'-azobis(2,4-dimethylvaleronitrile) (ADVN), 1,1'-azobis(1-cyclohexanecarbonitrile) (ACHN) , Dimethyl-2,2'-azobisisobutyrate (MAIB), 4,4'-azobis(4-cyanovaleric acid) (ACVA), 1,1'-azobis(1-acetoxy-1-) Phenylethane), 2,2'-azobis (2-methylbutylamide), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis ( 2-methylamidinopropane)dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis[2-methyl-N-(2 -Hydroxyethyl)propionamide], 2,2'-azobis (2,4,4-trimethylpentane), 2-cyano-2-propylazoformamide, 2,2'-azobis (N-butyl -2-methylpropionamide), 2,2'-azobis (N-cyclohexyl-2-methylpropionamide), and the like.

It is preferable to appropriately select these azo polymerization initiators according to reaction conditions. For example, 2,2'-azobis(2,4-dimethylvaleronitrile) (ADVN), 2,2'-azobis(4-methoxy-2,4 -Dimethylvaleronitrile), 2,2'-azobis(isobutyronitrile) (AIBN), 2,2'-azobis(2-methylbutyronitrile) in case of medium temperature polymerization (40 to 80°C) ( AMBN), dimethyl-2,2'-azobisisobutyrate (MAIB), 1,1'-azobis (1-acetoxy-1-phenylethane), 1,1' for high-temperature polymerization (80 ℃ or more) -Azobis(1-cyclohexanecarbonitrile) (ACHN), 2-cyano-2-propylazoformamide, 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2' It is preferable to use -azobis (N-cyclohexyl-2-methylpropionamide) and 2,2'-azobis (2,4,4-trimethylpentane), respectively. In addition, in the reaction using an aqueous solvent, 4,4'-azobis(4-cyanovaleric acid) (ACVA), 2,2'-azobis(2-methylbutylamide), 2,2'-azobis (2-methylamidinopropane)dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis[2-methyl-N-( It is preferable to use 2-hydroxyethyl)propionamide].

When an azo polymerization initiator is used, the amount used is usually 0.01 to 100 mol, preferably 0.1 to 10 mol, more preferably when the total amount of the organic tellurium compound represented by the above formula (1) is 1 mol. Is 0.1 to 5 mol.

A mixture of an organic tellurium compound represented by the formula (1) and an organic ditelluric compound represented by the formula (2), or an organic tellurium compound represented by the formula (1), an azo polymerization initiator, and an organic compound represented by the formula (2) When a dispersant is prepared using any of the mixtures of ditelluric compounds as a polymerization initiator, the prepared dispersant contains an organic telluric compound. For this reason, the total amount of tellurium in the dispersant can be measured by using a known metal measurement method such as an ICP emission analysis method and an atomic absorption method.

As the dispersant (A-B block polymer), it is preferable that the monomer constituting the A block is at least one type of monomer represented by the following formula (3), and the monomer constituting the B block is benzyl methacrylate and/or benzyl acrylate.

[Formula 3]

(In formula (3), R ⁵ represents a hydrogen atom or an alkyl group which may have a C 4 branch, and R ⁶ represents a hydrogen atom or a methyl group.)

Among the monomers represented by the above formula (3), R ⁵ is a hydrogen atom, R ⁶ is a methyl group; Or a monomer in which R ⁵ is an n-butyl group and R ⁶ is a methyl group is preferable. Moreover, it is more preferable to use these two types of monomers together.

The monomer constituting the B block is one or more kinds of monomers selected from benzyl methacrylate and benzyl acrylate, preferably benzyl methacrylate.

The acid value of the dispersant is usually 90 to 200 mgKOH/g, preferably 100 to 150 mgKOH/g, and more preferably 100 to 120 mgKOH/g. By setting it as such an acid value, dispersibility in water or a mixture of a water-soluble organic solvent and water tends to improve, and color development properties when coloring a recording material tend to be improved.

The mass average molecular weight of the dispersant is preferably from 10000 to 60000, more preferably from 10000 to 40000, and still more preferably from 15000 to 30000. By setting it as such a mass average molecular weight, the stability of a dispersion liquid tends to improve.

The ratio of the amount used of the dispersant to the total amount of the colorant is preferably 0.1 to 1, more preferably 0.1 to 0.6, and still more preferably 0.2 to 0.4 on a mass basis. By setting it as this amount, the stability of the dispersion liquid becomes good and there exists a tendency for the image quality of a recorded image to improve.

For the purpose of uniformly dispersing the dispersant in water, a neutralizing agent may be used. Examples of the neutralizing agent include alkali metal hydroxides, alkaline earth metal hydroxides, aliphatic amine compounds, and alkanolamine compounds.

Lithium hydroxide, sodium hydroxide, potassium hydroxide, etc. are mentioned as an alkali metal hydroxide. Examples of the alkaline earth metal hydroxide include beryllium hydroxide, magnesium hydroxide, calcium hydroxide, and strontium hydroxide. It is preferably an alkali metal hydroxide, more preferably lithium hydroxide or sodium hydroxide.

As an aliphatic amine compound, ammonia, monomethylamine, dimethylamine, trimethylamine, monoethylamine, dimethylamine, trimethylamine, etc. are mentioned. Among these, ammonia or triethylamine is preferable.

Examples of the alkanolamine compound include monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, methylethanolamine, dimethylethanolamine, and N-methyldiethanolamine. Among these, tertiary alkanolamine is preferable, and triethanolamine is more preferable.

The amount of the neutralizing agent is not particularly limited. The neutralization degree is 100% when neutralized with the theoretical equivalent of the acid value of the dispersant, and a neutralizing agent may be used in excess of the theoretical equivalent. The degree of neutralization is usually 50 to 200%, preferably 80 to 150%, and more preferably 100 to 120%.

When a dispersant having an acid value exceeding 200 mgKOH/g is used, the same effect as when a dispersant having an acid value lower than the acid value is used is sometimes obtained by setting the neutralization degree lower than 100% neutralization degree.

As a method of coating the dispersant on the surface of the colorant, a known method can be mentioned. The method is roughly divided into two types: a physical or mechanical method and a chemical method. Among the latter chemical methods, there are a surface precipitation method, a kneading method, an interfacial polymerization method, and the like. Here, the surface precipitation method is a method of depositing a dispersant on the surface of the colorant using pH adjustment or difference in solubility in a medium, and includes an acid stone method, an inversion emulsification method, and the like. The interfacial polymerization method is a method of performing a polymerization reaction after adsorbing a monomer, oligomer, or pigment derivative on the surface of a colorant, and is also called a surface polymerization method. Any of the above methods can be used, but among them, a surface precipitation method is preferable, and a full phase emulsification method is more preferable. In addition, in this specification, "coating a dispersing agent on the surface of a coloring agent" means coating a dispersing agent on at least a part of the surface of a coloring agent.

The average particle diameter of the colorant dispersed by the dispersant is usually 10 to 200 nm, preferably 50 to 150 nm, and more preferably 60 to 120 nm. By setting it as such an average particle diameter, while being excellent in dispersion stability and ejection stability, it is possible to increase the printing density of a recorded image. The average particle diameter can be obtained, for example, by measuring the dispersion using a laser light scattering method.

As a method of dispersing the colorant, a method using a sand mill (bead mill), a roll mill, a ball mill, a paint shaker, an ultrasonic disperser, a micro fluidizer, etc. can be exemplified. This is desirable. It is preferable to use beads with a small diameter (0.01 to 1 mm diameter) to prepare a dispersion liquid using a sand mill, and to perform treatment under conditions in which dispersion efficiency is increased by increasing the filling ratio of the beads. By performing dispersion under such conditions, the particle size of the colorant can be reduced, and a dispersion having good dispersibility can be obtained.

The prepared dispersion is also preferably carried out to remove solid components having a large particle size by a method selected from filtration, centrifugation, or the like.

In addition, when the foaming is intense in the preparation of the dispersion, a very small amount of an antifoaming agent such as silicone-based or acetylene glycol-based can be added. However, since there is an antifoaming agent that inhibits dispersion or micronization of the colorant, it is preferable to appropriately select and use the type of the antifoaming agent.

(Urethane resin)

When the color ink contains a water-insoluble colorant, it is preferable to further contain a urethane resin.

Urethane resins are often marketed in the form of latex (emulsion) and can be easily purchased. As a specific example of a commercial item, Pamarin UA-150, 200, 310, 368, 3945, latex of Ucoat UX-320 (above, manufactured by Sanyo Chemical Co., Ltd.), Hydran WLS-201, 210, latex of HW-312B (Above, manufactured by DIC Corporation), Superflex 150, 170, 470 (above, manufactured by Daiichi Pharmaceutical Co., Ltd.); And the like. Most of them are emulsions containing 30 to 60% of solid content.

Among the urethane resins, polycarbonate urethane resins are preferred. As a specific example of a commercial item of a polycarbonate urethane resin, Parmarin UA-310, 3945; Ucoat UX-320 etc. are mentioned, Among these, Ucoat UX-320 is preferable.

(Water-soluble organic solvent)

It is preferable that the color ink contains a water-soluble organic solvent. Examples of the water-soluble organic solvent include C1-C4 monools such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, second butanol, and third butanol; Ethylene glycol, propylene glycol, 1,3-propanediol, 1,2- or 1,4-butanediol, 1,3-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexane C2-C6 alkanediol such as diol; C3-C6 alkantriols such as glycerin, hexane-1,2,6-triol, and trimethylolpropane; Carboxylic acid amides such as N,N-dimethylformamide and N,N-dimethylacetamide; Heterocyclic ureas such as 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethylimidazolidin-2-one, and 1,3-dimethylhexahydropyrimide-2-one ; Ketones or keto alcohols such as acetone, methyl ethyl ketone, and 2-methyl-2-hydroxypentan-4-one; Linear or cyclic ethers such as 1,2-dimethoxyethane, tetrahydrofuran, and dioxane; Di- or tri-C2-C3 alkylene glycol or thioglycol such as diethylene glycol, triethylene glycol, dipropylene glycol, and thiodiglycol; Poly C2-C3 alkylene glycol with a repeating unit of 4 or more and a molecular weight of about 20000 or less, such as tetraethylene glycol, polyethylene glycol (preferably, a molecular weight of 400, 800, 1540, etc.), and polypropylene glycol (Preferably liquid); Polyglyceryl ethers such as diglycerin, triglycerin, and polyglycerin; Polyglycerol alkylene oxide adducts; Polyoxy C2-C3 alkylene polyglyceryl ethers such as polyoxyethylene polyglyceryl ether and polyoxypropylene polyglyceryl ether; Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether (butylcarbitol), triethylene glycol monomethyl ether, triethylene glycol monoethyl C1-C4 alkyl ethers of polyhydric alcohols such as ether and triethylene glycol monobutyl ether; cyclic esters or carbonates such as γ-butyrolactone and ethylene carbonate; Dimethyl sulfoxide; Acetic acid; And the like.

Moreover, it is preferable that the color ink further contains a polyglycerin alkylene oxide adduct, preferably a diglycerin C2-C4 alkylene adduct. As a commercial product of a diglycerin C2-C4 alkylene adduct, for example, SC-P400, SC-P750, SC-P1000, SC-P1200, SC-P1600, SC-E450, SC-E750, SC-E1000, SC -E1500, SC-E2000, SC-E3000, SC-E4500 (above, manufactured by Sakamoto Pharmaceutical Co., Ltd.); UniLube DGP-700, DGP-700F (above, manufactured by Nichiyu Corporation); And the like.

The content rate of the polyglycerol alkylene oxide adduct in the total amount of the color ink is usually about 0.5 to 2.5%, and preferably about 1 to 2%.

(Nonionic surfactant)

It is preferable that the color ink contains a nonionic surfactant. Examples of nonionic surfactants include polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, and polyoxyethylene. Ether systems such as alkyl ether; Polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate Ester system such as; 2,4,7,9-tetramethyl-5-decine-4,7-diol, 3,6-dimethyl-4-octine-3,6-diol, 3,5-dimethyl-1-hexin-3-ol Acetylene glycol (alcohol) systems such as; Sapinol 104, 105PG50, 82, 420, 440, 465, 485, DF-110D, Orphine STG (above, manufactured by Nisshin Chemical Industries, Ltd.); Polyglycol ethers, such as TergItol15-S-7 (manufactured by SIGMA-ALDRICH); And the like. Among these, an acetylene glycol surfactant is preferable.

As an acetylene glycol surfactant, for example, 2,4,7,9-tetramethyl-5-decine-4,7-diol, 2,4,7,9-tetramethyl-5-decine-4,7 -A surfactant selected from diol, 2,4-dimethyl-5-decin-4-ol, and 2,4-dimethyl-5-decin-4-ol or alkylene oxide adducts thereof is preferred. Examples of the alkylene oxide include a C2-C4 linear, branched, or cyclic alkylene oxide. Among these, a linear or branched alkylene oxide is preferable. As such surfactant, Orphine series (made by Air Products), such as Orphine 104 and E1010; Safinol series such as safinol 420, 440, 465, and 61 (manufactured by Nisshin Chemical Industries, Ltd.); And the like.

(Ink Formulation)

The color ink may further contain ink preparations other than the above, if necessary. Examples of ink preparations include anti-fog agents, preservatives, pH adjusters, chelating agents, rust inhibitors, water-soluble ultraviolet absorbers, water-soluble polymer compounds, and antioxidants.

(Content of each component)

Each of the components described above may be used singly or in combination of two or more. The content rate of each component in the total mass of the color ink (when it contains two or more types of compounds, the total) is, for example, as follows. In addition, the balance other than these is water.

Water-insoluble colorants:

Usually 1 to 15%, preferably 1 to 10%, more preferably 1 to 7%.

Dispersant:

Usually 0.1 to 15%, preferably 0.1 to 9%, more preferably 0.2 to 6%.

Urethane resin:

Usually 1 to 20%, preferably 3 to 15%, more preferably 3 to 12%.

Water Soluble Organic Solvent:

Usually 10 to 45%, preferably 20 to 45%, more preferably 30 to 40%.

Nonionic surfactant:

Usually 0.01 to 5%, preferably 0.05 to 3%, more preferably 0.2 to 2.5%.

Ink Formulation:

Usually 0 to 5%, preferably 0.1 to 2%, more preferably 0.2 to 1%.

(Surface tension)

The surface tension at 25°C of the color ink is usually 29 to 35 mN/m, and preferably 30 to 34 mN/m.

(How to prepare color ink)

The method for preparing the color ink is not particularly limited, and a known method can be employed. As an example, after preparing an aqueous dispersion liquid containing a water-insoluble colorant and a dispersant, another component is added and stirred. When the color ink contains a water-soluble dye, a method of adding and stirring necessary components without preparing a dispersion may be employed.

If necessary, the obtained color ink may be subjected to fine filtration by a known method to separate solid impurities by filtration. For example, when discharging color ink by an inkjet printer, it is preferable to perform microfiltration.

The ink set according to the present embodiment is very useful as an ink set for printing fibers because it is possible to form a color image with good non-printing when a color ink is adhered on a base formed with a back ink. .

<recording method>

The recording method according to the present embodiment using the above-described ink set is to perform recording by attaching each ink included in the ink set to a recording material. The method of attaching each ink to the recording material is not particularly limited, and a brush, brush, roll coater, bar coater, inkjet printer, or the like may be used depending on the purpose.

In the case of using an inkjet printer, recording can be performed by setting a container filled with each ink at a predetermined position of the inkjet printer, discharging droplets of each ink according to a recording signal, and attaching it to a recording material.

The nozzle or the like of the inkjet printer is not particularly limited, and can be appropriately selected according to the purpose. Moreover, the method of the inkjet printer is not particularly limited, either, and a known method, for example, a charge control method in which ink is discharged using an electrostatic attraction force; Drop-on-demand method using vibration pressure of piezo element (pressure pulse method); An acoustic ink jet method in which an electric signal is converted into an acoustic beam, irradiated to ink, and ink is discharged using the radiation pressure; A thermal ink jet method using the pressure generated by heating ink to form air bubbles; Etc. can be appropriately selected.

The material to be recorded is not particularly limited, but fibers and fabrics thereof are preferred.

The type of fiber is not particularly limited. Examples thereof include fibers selected from the group consisting of polyester, cellulose, polyamide, and natural fibers, or blended fibers thereof. Examples of polyester fibers include fibers containing polyethylene terephthalate as a main component. Examples of the cellulose fibers include cotton, cotton, rayon, triacetate fibers, and diacetate fibers. Examples of the polyamide fibers include nylon fibers. Examples of natural fibers include silk and wool.

The fiber may be formed with an ink receiving layer (spread prevention layer). A method of forming an ink-receiving layer on a fiber is known, and such fiber can be purchased as a commercial item. Moreover, it is also possible to form an ink-receiving layer on the fiber by appropriately selecting a constituent component, a forming method, and the like from a known common technique. The ink receiving layer is not particularly limited as long as it has the function.

After attaching each ink to the fiber, if necessary, baking (thermosol) treatment can be performed. As the baking treatment, conditions of usually 130 to 250°C, preferably 170 to 210°C, and usually 10 to 30 minutes, preferably about 60 to 180 seconds are mentioned. This method is also called dry heat fixation or the like.

For all the above-described matters, a combination of preferable ones is more preferable, and a combination of more preferable ones is even more preferable. The same applies to a combination of a preferable thing and a more preferable thing, a more preferable thing and a more preferable thing.

Example

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited only to these examples.

Each operation such as synthesis reaction and crystallization in Examples was all carried out under stirring unless otherwise noted. In addition, as for the temperature such as reaction, the internal temperature of the reaction liquid or the like was described.

In addition, "water" used in Examples is "ion-exchanged water" unless otherwise noted.

In addition, when measuring the solid content of the liquid, MS-70 manufactured by A&D Co., Ltd. was used, and it was determined by the dry weight method. The content of the coloring agent is the content of only the coloring agent in terms of the total content of the solid content contained in the dispersion.

[Examples 1 to 5 and Comparative Examples 1 to 7: Preparation of white ink]

The components described in Table 1 below were sufficiently stirred and mixed to obtain a back ink. After filtering the obtained bag ink with a filter of mixed cellulose ester having a pore diameter of 5 µm, degassing was performed using a vacuum pump to obtain a test bag ink W1.

The numerical value in the following Table 1 means "part" and is a solid content conversion value.

Symbols and the like in Table 1 below have the following meanings.

TiO ₂ = TF-5760 WHITE (D2B) (Titanium oxide slurry manufactured by Dainichi Purification Industries, Ltd., titanium oxide solid content concentration: 60%, average particle diameter: 300 nm)

UX320 = Ucoat UX-320 (Polycarbonate urethane resin manufactured by Sanyo Chemical Industries, Ltd., solid content concentration: 40%)

UA-150 = Parmarin UA-150 (Polyetherurethane resin manufactured by Sanyo Chemical Industries, Ltd., solid content concentration: 30%)

UWS-145 = Ucoat UWS-145 (Sanyo Chemical Industry Co., Ltd. polyester urethane resin, solid content concentration: 36%)

UX-390 = Ucoat UX-390 (Polycarbonate urethane resin manufactured by Sanyo Chemical Industries, Ltd., solid content concentration: 38%)

UA-368 = Parmarin UA-368 (Polycarbonate urethane resin manufactured by Sanyo Chemical Industries, Ltd., solid content concentration: 50%)

WLS-201 = Hydra WLS-201 (polycarbonate urethane resin manufactured by DIC Corporation, solid content concentration: 35%)

R967 = NeoRez R-967 (Polyetherurethane resin manufactured by Kusumoto Chemical Industries, Ltd., solid content concentration: 40%)

GL = glycerin

PG = propylene glycol

SF104 = Safinol 104PG50

LA-10 = Hightenol LA10

DYNOL = Dynol 604

TEA = Triethanolamine

GXL(S) = PROXEL GXL(S)

[Preparation of pretreated fiber]

Senka Co., Ltd. Unisense KHE100L (solid content: 60%, 15 parts), Nippon Synthetic Chemical Co., Ltd. Movinyl 6960 (solid content: 45%, 1.5 parts), and Daiichi Kogyo Pharmaceutical Co., Ltd. Epan U-103 Water was added to (0.15 parts), the total amount was 100 parts, and mixed to obtain a fiber pretreatment solution.

A 100% cotton T-shirt (Printstar heavy-weight, black fabric manufactured by Toms Corporation) was coated with a roller in A4 size so that the amount of the obtained pretreatment solution adhered was 0.025 g/cm 2 in a coating amount per unit area. The obtained T-shirt with the pretreatment liquid was subjected to heat treatment at 150°C for 30 seconds with a heat press to obtain pretreated fibers.

[Preparation of Evaluation Fiber]

With respect to the pretreated portion of the pretreated fiber obtained as described above, each ink of Examples 1 to 5 and Comparative Examples 1 to 7 was discharged by an industrial inkjet evaluation device (expansion type coating device EV2500: manufactured by Ricoh Corporation). , A white solid pattern image was inkjet recorded. The head temperature at this time was recorded twice at 25占폚 and a resolution of 1200 x 2400 dpi. Each fiber for evaluation was obtained by performing heat treatment at 150° C. for 4 minutes with a hot air dryer on the obtained fiber to which the back ink was adhered.

The following evaluation test was performed on the evaluation fiber obtained as described above.

The evaluation results of each test were shown in Table 2 below.

[Evaluation of whiteness]

Evaluation of whiteness was performed by measuring the L* value of the evaluation fiber. As a colorimeter, eXact manufactured by X-Rite was used, and L* values in a CIE/L*a*b* colorimeter were measured. As for the colorimetric condition at this time, the observation light source was D65, the observation field of view was 2°, and the density was Status T. Each evaluation fiber was subjected to colorimetry 5 times, and the average value was taken as the measurement result. The larger the L* value is, the higher the whiteness is, so it is preferable.

[Evaluation of cracks]

The fiber for evaluation was stretched to the limit with both hands so as not to tear the fiber, was held for 3 seconds, and then the stretching was stopped. The crack of the white solid pattern image of the fiber was visually observed, and the state was evaluated by the following three evaluation criteria.

- Evaluation standard -

A: Cracks due to stretching were not observed in the image.

B: The image cracked slightly by stretching, and the color black of the dough was observed slightly.

C: The image was cracked by stretching, and black color of the dough was clearly observed.

[Evaluation of image unevenness]

The white solid pattern image of the evaluation fiber was visually observed, and image unevenness was evaluated by the following three evaluation criteria.

- Evaluation standard -

A: No unevenness was observed on the image.

B: In the image, a little unevenness was confirmed, and although it was white, there was a part in which light and shade appeared.

C: In the image, unevenness was confirmed, there was a portion where the white ink was adhered excessively, and the portion where the white ink was not adhered and the color black of the raw paper was clearly observed.

From the results shown in Table 2, the fibers using the back ink of Examples 1 to 5 have higher whiteness compared to the fibers using the back ink of Comparative Examples 1 to 7, and hardly generate cracks due to stretching, It was found that the non-uniformity of was very small.

[Preparation Examples 1 to 2: Preparation of white ink]

The components shown in Table 3 below were sufficiently stirred and mixed to obtain a back ink. After filtering the obtained bag ink with a filter of mixed cellulose ester having a pore diameter of 5 µm, degassing treatment was performed using a vacuum pump to obtain test bag inks W1 and W2.

The numerical value in Table 3 below means "part" and is a value in terms of solid content.

Symbols and the like in Table 3 below have the following meanings.

TiO ₂ = TF-5760 WHITE (D2B) (Titanium oxide slurry manufactured by Dainichi Purification Industries, Ltd., titanium oxide solid content concentration: 60%, average particle diameter: 300 nm)

UX320 = Ucoat UX-320 (Polycarbonate urethane resin manufactured by Sanyo Chemical Industries, Ltd., solid content concentration: 40%)

R967 = NeoRez R-967 (Polyetherurethane resin manufactured by Kusumoto Chemical Industries, Ltd., solid content concentration: 40%)

GL = glycerin

PG = propylene glycol

604 = Dynol 604

TEA = Triethanolamine

GXL(S) = PROXEL GXL(S)

[Synthesis Example 1: Synthesis of Dispersant]

According to "[Synthesis Example 3] Synthesis of Block Copolymer A" in International Publication No. 2013/115071, 138 g of a dispersant having a mass average molecular weight of 24300 and a PDI of 1.49 was obtained. In the obtained dispersant, the monomer constituting the B block is benzyl methacrylate, the monomer constituting the A block is a monomer in which R ⁵ is a hydrogen atom and R ⁶ is a methyl group in the monomers represented by the above formula (3), and R These are two types of monomers in which ⁵ is an n-butyl group and R ⁶ is a methyl group.

[Preparation Example 3: Preparation of a dispersion containing a coloring agent]

The dispersant (6.3 parts) obtained in Synthesis Example 1 was dissolved in 2-butanone (20 parts) to obtain a solution. To this solution, a solution obtained by dissolving 0.47 parts of sodium hydroxide in water (51.45 parts) was added and stirred for 1 hour to obtain an emulsion. C.I. Pigment Yellow 155 (21 parts) was added, and dispersion treatment was performed for 15 hours under water cooling and conditions of 1500 rpm with a sand grinder to obtain a liquid. The obtained liquid was diluted with ion-exchanged water, and the beads for dispersion were separated by filtration to obtain a filtrate. This filtration separation was carried out in two layers so that GA100 of the glass filter paper manufactured by Advantech Co., Ltd. was above and GC50 was below. Part of 2-butanone and water in the obtained filtrate was distilled off under reduced pressure with an evaporator to obtain a dispersion having a colorant content of 12%. This dispersion is referred to as "DP1".

[Preparation Examples 4 to 6: Preparation of a dispersion containing a coloring agent]

Except replacing each component used in Preparation Example 3 with the components and usage amounts shown in Table 4 below, in the same manner as in Preparation Example 3, DP2 to DP4 as dispersions of Preparation Examples 4 to 6 were obtained, respectively. In addition, the numerical value of each component was "parts", and the amount of water added was adjusted so that the total content of the coloring agent in each dispersion liquid might be 12%.

Symbols and the like in Table 4 below have the following meanings.

PY155 = C.I. Pigment Yellow 155

PR122 = C.I. Pigment Red 122

PB15:4 = C.I. Pigment Blue 15:4

CB = carbon black

DpA = dispersant synthesized in Synthesis Example 1

MEK = 2-butanone

NaOH = sodium hydroxide

[Preparation Examples 7 to 10: Preparation of color ink]

Each of the components shown in Table 5 below was mixed, stirred sufficiently, and then filtered through a membrane filter having a pore diameter of 3 μm to obtain inks of Y1, M1, C1, and K1 used in the evaluation test. In addition, the numerical value of each component was "parts", and the amount of water added was adjusted so that the total might be 100 parts.

The abbreviations and the like in Table 5 below have the following meanings.

UX320 = Ucoat UX-320 (Polycarbonate urethane resin manufactured by Sanyo Chemical Industries, Ltd., solid content concentration: 40%)

PG = propylene glycol

GL = glycerin

DGA = SC-P1000

TEA = Triethanolamine

SF420 = Safinol 420

SF104 = Safinol 104PG50

GXL(S) = PROXEL GXL(S)

[Preparation of pretreated fiber]

Senka Corporation Unisense KHE100L (dimethylamine, ammonia, epichlorohydrin polycondensate, solid content concentration: 60%, 7.5 parts), Nippon Synthetic Chemical Co., Ltd. Movinyl 6960 (styrene/acrylic resin emulsion, solid content concentration: 45) %, Tg = -23°C, 0.75 parts), and Daiichi Kogyo Pharmaceutical Co., Ltd. Epan U-103 (0.075 parts) were added with water to make a total amount of 100 parts and mixed to obtain a fiber pretreatment solution.

A 100% cotton T-shirt (Printstar heavy-weight, black fabric manufactured by Toms Corporation) was coated with a roller in A4 size so that the amount of the obtained pretreatment solution adhered was 0.025 g/cm 2 in a coating amount per unit area. The obtained T-shirt with the pretreatment liquid was subjected to heat treatment at 150°C for 30 seconds with a heat press to obtain pretreated fibers.

[Preparation of Evaluation Fiber]

For the pretreated portion of the pretreated fiber obtained as described above, a garment printer (manufactured by Muto Industries Co., Ltd.: VJ-405GT) was used, and the back ink was discharged in a print setting mode of 600 × 1200 dpi, and the back ink To obtain the attached fiber. After the back ink, the color ink was discharged using a garment printer (manufactured by Muto Industrial Co., Ltd.: VJ-405GT) in a print setting mode of 600 x 1200 dpi to obtain fibers with color ink. The obtained fibers were subjected to heat treatment at 150° C. for 4 minutes with a hot air dryer to obtain each fiber for evaluation.

[Colorimetric condition]

When colorimetry is required for the fiber for evaluation test obtained as described above, a spectral density and colorimeter manufactured by X-Rite, X-Rite eXact is used, the observation light source is D65, the observation field is 2°, and the density is ANSI. Coloration was performed under the condition of T. In addition, colorimetry was performed with a CIE/L*a*b* color system.

[Private printing evaluation test of color ink]

For the fiber for evaluation test, the degree of non-printing of each color image was visually checked, and evaluated according to the following three-step criteria. The evaluation results are shown in Tables 6 and 7 below.

- Evaluation standard -

A: No white line was confirmed, and the print was good.

B: There is a part where the white line can be confirmed, but the plain print was relatively good.

C: There is a part where the white line can be clearly confirmed, and the private printing is not good.

D: A large number of white lines were confirmed, and it was not printed.

[Surface tension measurement]

The surface tension of the ink was measured by the plate method in an environment at room temperature of 25°C using a CBVP-Z type surface tension meter manufactured by Kyowa Interface Science Co., Ltd. The measurement results are shown in Tables 6 and 7 below. The unit of surface tension in each table is "mN/m".

From the results shown in Tables 6 and 7, it was found that the fibers using the ink sets of Examples 6 to 9 had good non-printing of color ink compared to the fibers using the ink sets of Comparative Examples 8 to 11.

Claims (13)

A white pigment, a polycarbonate urethane resin, a polyether urethane resin, and a bag ink containing water. The method of claim 1,
Back ink further containing a water-soluble organic solvent. The method according to claim 1 or 2,
Back ink containing additional surfactants. The method of claim 3,
Back ink wherein the surfactant is at least one surfactant selected from acetylene glycol and polyalkylene glycol. The method according to any one of claims 1 to 4,
A back ink having a total content of 10 to 20 mass% of the polycarbonate urethane resin and the polyether urethane resin. It comprises the back ink according to any one of claims 1 to 5 and one or more kinds of color inks,
The color ink is an aqueous ink containing a colorant other than a white pigment,
An ink set in which the difference in surface tension between the back ink and the color ink at 25° C. is ±0 to 3 mN/m. A recording method in which recording is performed by attaching the back ink according to any one of claims 1 to 5 to a recording material. The method of claim 7,
A recording method in which recording is performed by discharging the back ink by an ink jet printer and attaching it to the recording material. A recording method in which recording is performed by attaching each ink included in the ink set according to claim 6 to a recording material. The method of claim 9,
A recording method for performing recording by discharging each ink included in the ink set by an ink jet printer and attaching it to the recording material. The method according to any one of claims 7 to 10,
The recording method wherein the recording material is a fiber selected from the group consisting of polyester fibers, cellulose fibers, polyamide fibers, and natural fibers, blended fibers containing these fibers, or fabrics containing these fibers. The fiber to which the back ink according to any one of claims 1 to 5 is adhered. A fiber to which both of the back ink and one or more kinds of color inks provided in the ink set according to claim 6 are adhered.